# This requires the free xml-rpc library available from
# http://www.pythonware.com/products/xmlrpc/
#
# See Examples/XMLRPCExample.py for sample usage.
#

# Sometimes xmlrpclib is installed as a package, sometimes not.  So we'll
# make sure it works either way.
try:
    from xmlrpclib import xmlrpclib
except ImportError:
    import xmlrpclib
import sys, string, traceback
from RPCServlet import RPCServlet

class XMLRPCServlet(RPCServlet):
    """
    XMLRPCServlet is a base class for XML-RPC servlets.
    See Examples/XMLRPCExample.py for sample usage.

    For more Pythonic convenience at the cost of language independence,
    see PickleRPCServlet.
    """
    def respondToPost(self, transaction):
        """
        This is similar to the xmlrpcserver.py example from the xmlrpc
        library distribution, only it's been adapted to work within a
        WebKit servlet.
        """
        try:
            # get arguments
            data = transaction.request().rawInput(rewind=1).read()
            encoding = _getXmlDeclAttr(data, "encoding")
            params, method = xmlrpclib.loads(data)

            # generate response
            try:
                # This first test helps us to support PythonWin, which uses
                # repeated calls to __methods__.__getitem__ to determine the
                # allowed methods of an object.
                if method == '__methods__.__getitem__':
                    response = self.exposedMethods()[params[0]]
                else:
                    response = self.call(method, *params)
                if type(response) != type(()):
                    response = (response,)
            except Exception, e:
                fault = self.resultForException(e, transaction)
                response = xmlrpclib.dumps(xmlrpclib.Fault(1, fault), encoding=encoding)
                self.sendOK('text/xml', response, transaction)
                self.handleException(transaction)
            except:  # if it's a string exception, this gets triggered
                fault = self.resultForException(sys.exc_info()[0], transaction)
                response = xmlrpclib.dumps(xmlrpclib.Fault(1, fault), encoding=encoding)
                self.sendOK('text/xml', response, transaction)
                self.handleException(transaction)
            else:
                response = xmlrpclib.dumps(response, methodresponse=1, encoding=encoding)
                self.sendOK('text/xml', response, transaction)
        except:
            # internal error, report as HTTP server error
            print 'XMLRPCServlet internal error'
            print string.join(traceback.format_exception(sys.exc_info()[0],sys.exc_info()[1],sys.exc_info()[2]))
            transaction.response().setStatus(500, 'Server Error')
            self.handleException(transaction)



# Helper functions

def _getXmlDeclAttr(xml, attName):
    """ gets attribute value from xml declaration (<?xml ... ?>) """
    s = xml[6 : xml.find("?>")] # 'version = "1.0" encoding = "Cp1251"'
    p = s.find(attName)
    if p==-1:
        return None
    s=s[p+len(attName):]        # '= "Cp1251"'
    s=s[s.find('=')+1:].strip() # '"Cp1251"'
    return s[1:s.find(s[0],1)]  # 'Cp1251'